Preparation of 6alpha-methyl-17alpha-hydroxyprogesterone and 17alpha-esters thereof



' United States Patent 3,043,832 PREPARATION OF 6a-METHYL-17a-HYDROXY- PROGESTERONE AND 17a-ESTERS THEREOF Pietro de Ruggieri and Carlo Ferrari, Milan, Italy, as-

signors to Ormonoterapia Richter S.p.A., Milan, Italy,

a corporation of Italy 7 No Drawing. Filed Apr. 28, 1961, Ser. No. 106,165

Claims priority, application Italy Feb. 27, 1961 4 Claims. (Cl. 260-23955) The present invention relates to the preparation of compounds represented by the formula H, wherein R is hydrogen or an acyl radical derived from aliphatic carboxylic acid having 2-7 carbon atoms, which have high progestative activity in the human and veterinary field. As starting material, 3 B-acetoxy-5a,6a-oxide- 17 B-cya'n-17a-(2'- tetrahydropyranyloxy)-androstane (see copending application Serial No. 763,799, filed September 29, 1958, now Patent No. 2,996,502) has been selected.

This compound upon treatment with methyl magnesium bromide or iodide yields, after decomposition of the ZO-ketimine with boiling aqueous solution of ammonium chloride, the oily 6fl-met hyl-17u-(2'-tetrahydropyranyloxy)-pregnane-3,8,5u-diol-20-one. This, when hydrolyzed with an acid such as hydrochloric, sulfuric or ptoluenesulfonic acid, yield '6B-methy1-pregn'ane-3fi,5a-17atriol-20-one; However it treated with aluminum isopropoxide or t-butoxide and cyclohexanone in boiling toluene, the intermediate tetrahydropyranyl ether yields 60:- methyl 17a methyl-17a-(2-tetrahydropyranyloxy)-4- pregnene-3,20-dione.

This compound, when hydrolyzed with an acid such as hydrochloric, sulfuric or p-toluenesulfonic acid, yields 6a-methyl-4-pregnene-17a-0l-3,20-dione but when treated with aliphatic carboxylic acids having 2-7 carbon atoms or their anhydrides in the presence of catalytic amounts of p-toluenesulfonic acid, it yields the corresponding 17aacyloxy-derivative of 6u-methyl-4-pregnene-17a-ol-3,20- dione. The following examples are given to further illustrate the products and the process of the present invention, and are not to be construed as limiting.

EXAMPLE 1 6/3 Methyl-17a-(2' Tetrahydropyranyloxy) Pregnane- 3,8,5a-Di0l-20-One and 6,8-M ethyl-Pregnane-j'fij 11,] 7a- Trial-ZO-One A solution of 1.0 part of 3fi-acetoxy-5a,6a-oxideandrostane17}8-cyan-17a-(2-tetrahydropyranyloxy) in 30 parts of anisole was treated with 50 parts of an ethereal solution of methyl magnesium bromide (from 3.3 parts of magnesium).

The ether was removed and the mixture kept at 90-95 C. for 16 hours. After decomposition with 100 parts of ice cooled 10% ammonium chloride aqueous solution, the mixture was refluxed for minutes; then, after ethereal extraction, the solvent was removed to dryness in vacuo. The oily residue, which resisted crystallization attempts, showed LR. bands at 2.90 1 (free hydroxyl), 5.85 (ZO-keto), and 10.16, 11.45,u (pyranyl-ether).

3,043,832 Patented July 10, 1962 A sample, boiled for 15 minutes in acetone with a drop of dilute hydrochloric acid, gave 6p-methyl-pregnane- 3p,5u,17a-triol-20-one M.P. 247-249 C., [ab-34 (Chfr); LR. bands: 2.90 (hydroxyl), 5.88 1. (ZO-keto).

EXAMPLE 2 6a Methyl-17oc-(2'- Tetrahydropyranyloxy)-4-Pregnene- 3,20-Di0ne and 6a-Methyl 4 Pregnene-17a-0l-3,20- Dione 1.2 parts of GB-methyl-17w(2 tetrahydropyranyloxy)- pregnane-3l3,5a-diol-20-one were dissolved in 35 parts of toluene and 10 parts of cyclohexanone 2.4 parts of aluminum isopropoxide, dissolved in 24 parts of toluene, were added and the mixture was refluxed for 1 hour. After cooling, 60 parts of Rochelle salt in 90 parts of water were added, the aqueous phase was decanted and the organic phase was steam-distilled until the solvent was completely eliminated. The remaining aqueous suspension was repeatedly extracted with diethyl ether and the combined extracts, after drying over sodium sulfate, were concentrated to dryness. The residue was dissolved in benzene and filtered through a short column filled with 10.0 parts of aluminum oxide. The oily residue, obtained after solvent elimination, was crystallized from aqueous methanol to give Got-methyl-17u-(2'-tetrahydropyranyloxy) 4-pregnene-3,20-dione M.P. 138-143 C., [u] +72 (acetone); LR. bands: 5.88 (20-keto); 6.01, 6.25 (3-keto-A 10.16, 11.45; (pyranyl-ether).

A sample boiled for 15 minutes in acetone with a drop of dilute hydrochloric acid, gave 6a-methyl-4-pregnene 17a-ol 3.20-dione M.P. 218222 C., [a] +73 (Chf.);

LR. bands: 2.90 (free hydroxyl), 5.97 0 (20-keto), 6.01, 6.25; (3-keto-A EXAMPLE 3 6a-Methyl-1 7a-Acet0xy-4-Pregnene-3.ZO-Dione 20 parts of the 6a-methyl-17a-(2'-tetrahydropyranyloxy)-4-pregnene-3,20-dione were dissolved in 20 parts of pure acetic acid and 0.15 part of p-toluenesulfonic acid were added.

The mixture was refluxed for 6 hours, then cooled and diluted with water.

After extraction with diethylether, the organic phase was washed with 2 N aqueous solution of Na CO and water, dried over Na SO, and concentrated in vacuo to dryness. Crystallization from methanol gave Got-methyl- 17a-acetoxy-4-pregnene-3,20-dione M.P. 207-209 C., ]D+

A223? 240 m (15,900) LR. bands: 5.78, 8.01,:1. (17a-acetoxy), 5.88; (20-keto), 6.01, 622 (3-keto-A EXAMPLE 4 6 a-M ethyl-1 7u-Hexanoyl0xy-4-Pregnene-3,ZO-Dione 2.0 parts of 6a-methyl-17a-(2'-tetrahydropyranyloxy)- 4-pregnene-3,20-dione were dissolved in 20 parts of caproic anhydride and 0.15 part of p-toluenesulfonic acid were added. The mixture was kept at 110 C. for 16 hours, then diluted with water containing a few drops of 3 LR. bands; 5.78, 8.12;(17a-hexanoyloxy), 5.85 1, (20- keto); 6.01, 623p (3-keto-A EXAMPLE 5 6 a-M ethyl-1 7 a-H ep tanoy l 0xy-4 -Pregnen e-3 ,2 0-D ione AEtOH max.

l7fl-cyan-17a-(2'-tetrahydropyranyloxy) -androstane with t a methyl magnesium halide selected from the group consisting of methyl magnesium bromide and methyl magnesium iodide, decomposing the reaction product with ammonium chloride to yield 6 8-methyl-17a-(2'-tetrahydropyranyloxy)-pregnane 313,50 diol-2 0-one, oxidizing said last-named compound with cyclohexanone and an aluminum 'alkoxide selected from the group consisting of aluminum isopropoxide and aluminum t-butoxide, and treating the resulting 6a-rnethyl 17a (2-tetrahydropyranyloxy)-4-pregnene-3,20-dione with an acid selected fromthe group consisting of hydrochloric acid, sulfuric acid and p-toluenesulfonic acid to yield 6a-methyl-4-pregnene- 17a-ol-3,20-dione.

4. A method of preparing compounds of the formula wherein R is an acyl radical derived from an aliphatic carboxylic acid having 2-7 carbon atoms, comprising reacting 3p acetoxy-5a,6a-oxide-l7fi-cyan-l7m-(2'-tetrahydropyranyloxy)-androstane with a methyl magnesium halide selected from the group consisting of methyl magnesium bromide and methyl magnesium iodide, decomposing the reaction product with ammonium chloride to yield 6,8-methyl-17a- (2-tetrahydropyranyloxy) -pregnane- 3,8,5a-diol-20-one, oxidizing said last-named compound with cyclohexanone and an aluminum alkoxide selected from the group consisting of aluminum isopropoxide and aluminum t-butoxide, and treating the resulting 6a-methyl-l7a-(2-tetrahydropyranyloxy)-4-pregnene 3,20 dione with a compound selected from the group consisting of an aliphatic carboxylic acid having 2-7 carbon atoms and an anhydride thereof in the presence of catalytic amounts of p-toluenesulfonic acid to obtain the corresponding l7a-acyloxy derivative of 6o-methyl-4-pregnene-l7a-ol- 3,20-dione.

References Cited in the file of this patent UNITED STATES PATENTS 2,753,360 Kaspar et a1. July 3, 1956 2,889,342 Loken June 2, 1959 2,892,833 Miramontes et al. June 30, 1959 2,959,585 Ruggieri et al. Nov. 8, 1960 OTHER REFERENCES Babcock et al.: I.A.C.S., 80, 2904-2905 (1958). I Ruggieri et al.: J.A.C.S., 81, 5725-27 (1959).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,043,832 July 10 1962 Pietro de Ruggieri et a1 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1 lines 13 to 24, the formula should appear as shown below instead of as in the patent:

Signed and sealed this 11th day of December 1962.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

4. A METHOD OF PREPARING COMPOUNDS OF THE FORMULA 